Dental cement

ABSTRACT

161,868. Schiff, S. June 16, 1920. Addition to 145,052. Metallic-oxide cements; plastic compositions containing oxychlorides; plastic compositions containing soluble silicates. - Colloidal silicic acid, either in the sol condition or as hydrogel, acetogel or alcogel, is added to certain classes of dental cements to increase their hardness and transparency. The cements in question are those composed of zinc oxide and a solution of zinc chloride or sulphate or a phosphate, and those containing silicates or polysilicates with oxides, phosphates, borates, &amp;c., of various metals and a solution of phosphoric acid. Ths colloidal silicic acid may be added either to the solution or to the solid ingredient of the cement, or to both, or it may be used alone with metallic oxides.

I06. COMPOSITIONS,

COATING R PLASTIC.

.1 9 9"w sis ioibnwing. i 1 w a TocZ Z zb Izomitrnm voneernk 5 -1;

ist, a. citizen of Germany,an'd resident ,of Karlsruhe,'Baden Germany,with the post- 5 ofiice address 15 'Ettlingerstrasse, have 1n- L-F'vented new and useful lmfimvements.in,;;

Dental Cements, (for which have filed applicationsin Germany May 5,1917, application 'No. 5l,37.0,with priority of June'12, 10 1918,'aplication-No; 54,384; Austria June 11,1919; ungary J u1y8, 1919;Switzerland June 12, 1919; Netherlands June 18,1919; Sweden'June 12,1919; Denmark July 14, 1919; Belgium June 25, 1919;Trance June 26, 1919;Cze'cho-Slovakia Aug. 19, 1919,) 1 of-which the following is aspecification. For filling teeth there are used masses madeby mixing apowder with aliquid, the com tion being such that it hardens to a solicement. -61 g5 1 1 According to the chemical composition of the powderor the liquid such fillings may be ssified under five groups as followsZincchloride cements, in-which the pow er consists essentiallyof zincoxide and on the liquidoijan aqueous am so lut n. 1 I l Zinc sulphatecements, 'i nwhich'the er again consists of zinc oxide and the P 80 liq'd of ing spjpha? solution. to; kg Zmc""ox1 e -p osphate cements, :in

thepowder nsists of a zinc oxide 7 q A gmd the liquid ofza so ution of ap osp 0112 it ;is nottransparent' and gtherefore th agl'qflgiraphosphate. 11 l 85 n. ese reegmupsthere isformed by' Applicationnea'inu a, 1920. mun-1i 195914.

Cross Reierence mm, or immense, .senmm. 5 I

I 5fi armseisus ses J. resident, 1922.

hardened continue for it'known that I, ZSAILTSCHHT, chem sometime-longer to eliminate acid. '1 rggzfl his'elimination of acid is aconsiderable hindrance to the use of these fillings,- since it givesErise to injury of the pulp. In order to prevent this a s tum of basiczinc i oxide compounds must eglven t e mg. A e e ation of :acidfis-toexplained by thefact-that-there-is no chemical union ofthe phosphoricacid but only an adsorpti'onlthereof. 1 1- As already stated, in thesilicateicements, the silicic;acid does not enter into reaction.

Indeed it isalready combined v'rith a metal 11 5" r, g,:-':; Porcelainand lass aremcu e L ereony or been' added togthe efirst fourg,,groups,-abut merely to increase the hardness of theixmxe -ture,-just as'the;gravel added -toconcrete in 8 5 .creases the mechanicaljhardness. j

The disadvantage ofthefsilicaadd' h a up certain-extent in, m inejdOOIIditiQn,-is tha.t V

ment b s l; und r b app ar nc .Lz Lhe present.- invention isba,sed onthe ob;

Oil bringing together the powder and the liquid 'aervationethat -the useof silicic. acid in1 co1- g,

qu correct. '.The group does {not contain .40 cements whichsilicic acidtakes ipart'in a. a; reaction onbringing together a powdery-and =lc1umma ne- 1um ,;an er orates 0s ates. Rides and .mol ma'fi oifliedoregomg 55 E i e, o e s, mwi 'p P 9 59 @idwn i m a d salts nfi red lvsilicates..and also oxides of g, ble compound which ha rdens loida conditionthatgis M rae Silicate cements. This title is not no as 1 ,givesrlseto.-'a I1umberoIcons1dloidal silieie-ucid however', in casesinwwhiehDemise e hardness .i sf a dva ne .phos horicacid 'or an acid hos hate isused lime-[Eng the cement; 1t ri] 5; remembered 106 that in these: cases(there is the undesirable Ink-hale inffli reult th t'e idtiesl mifi td een e t J the ho horicacid maybe figedby entering 110* n F intfime activesilicic forming mm astieemsaeznh chxharden; aim aqmPQaeds-swees ll eshwhr e pho i 106. COMPOSITIONS,

COATING OR PLASTIC.

""This" ol sili Fhos horic acid and" the known pow ers, sum asavebeen'mamed above, form the silicate cements, i. e., com- 'poundswhich do not eliminate aaciid and, owing to their at hardness, exhibitavhigh stability in presence of allialine as Moll as *ac-id liquids. f'Acoording tothe compositionofthe powder cements of high'tmnsparency mayobtained. I

I {The colloidal silicic acid inaylbedlised as so hv ro e ace 0 e or acoge. t may mer e e53 ed t5 t l e powd'm the latter then mixed with asolution of ghos g'horic acidcr the powder (oxides, silicates ipoysilicates) may be treated withfacolloidal solation of the silicicacidin'phosphoric;acid or an acid hos hate. Again colloidalsilicic acidmaylie ad a elther tothepowder'or to 't'hediquid. It is also practicable to'ilse as the liquid an emulsoid o'r suspensoid -cf 4 "phosphoric acidor'an acid salt thereof with hydro'gel, acetoge'l or alc'ogelo'f silicicacid. 80 -Iif necessa'ry. colouring matter maybe added "When colloidalsilicic acid is used not for the purpose'of fixing free acid but*o'nly'for enhancing the-transparency and'ha'rdne'ss of themass. it maybe applied incombinati'on 85 with acids, salts or "bases, hutalsowithout th'ese, that is't'o say only with metal oxide's or -th'e'li'ke.I 'Itmay inons h drates of'silicon dioxideithat s to 40 'say colloldaIs1lic1c and. dissolve 1n solutions 0f tun states and sihcotun tates;moreover, I e aceoge 0 "s1 1c1c -ac1 possible'to use at the same "timeany other 'sfiitahle acid which may 'disfflace"the "water in thehydrogel. Againfithe water in -the V hydrogel 'mayserve as solt entforip'artimilar ;sa1ts. For instance, mi mol 'bclic lved 1n "ac'd oi-tunstic acid may disso hydrogeI, or magnesluni chlorideQz'inc chlo- 'iid'e'zin'c' sulphate or' the like.

' These compounds fand, 'ls'phsoids and ifnilsoids ofsilicic acid, andalso phosphoric 'ticiti'in combination with silicic acidfinay be usedalone for making i cein'ents'. The following examples illiistrates th isentry- 1 I 4 4Ad'dition of colloidal silicic fie I o e p w'de'r." I g:

50 grams of magnesium sulphaite and grams of a l'uniininm sulphate aredissolted in water and 100 grems of sodium silicate 'in acid?'ihligmiislelimn be stated,- for e'iiam ilefthat gg'iat- 170 per cent ofwater) are added. ghema ssiswashedand brought to the consistency 6Tjia-std'b'y pressing out the water. {Ilgfle product is used as a paste.

I I 1d. J a (0)."32 "grams of aluminium"'hydro"xide lreintimatelyanizxedwith 20 gramszefsilicic acid acetogel and 150 grams of water, and themixture 15% py oph'osphor-ic acid Bysstr-on'gly lieating-e clearsolution is obtainedg '-'-(b) 'To-this clear solution are-Qdded m 'gramsof the aeetogel (50 per cent aeidwontent) and the *w-hole' is'groundina-bla ll mill or threehonr's (suspensoid); I A

v zm Addition'of colloidal silicic ac v -o powderend-liquid. (1

dium'siIicate -aregmund wet-with 3.5g'rains o calcium hydroxide; and 15grams of aluminiu 'in silicate, and the mixtur is-dried and heetedtofincandesdencen "The powder obtained "is i' 'tiihatelyinifed 5 withsufficient 'alcogel ofsilicic'acid'topro- *ducea still paste. r

(1)) Liquid. 16 grams of acid aluminium phosphat'e are inest intimatelyground-in a ball-mill with l grams of waten and ti grams of' SiIicicacid-amte'geI *(50 'pe' east acid content) Eq'am (6) Liquid. '50dfsllicic acidfg'el 1 saturated with zinc chloride. I P f 01!) e7,uickly tofineiin eseence;

saturated with magnesiumchloridei I Having thus fully descrihedtfhe-nathi'eiif the said invention and the' liestineahsl know get-her@ulteiijileflt metallic compounds i-li uids capable ofpmduci g'fienptcements, 120

' w' ich comprises adding 'sili'cic" a'eidin coliii kiiig dental cements1 m a d'e bimgiii'g together fiwemlht metallieeoinpounds mid 125 iiu'ids capitgeitfpman i' iientalceiiients The finipibtmentfin the"processof ifizll'r'ing dental izmehts iiihdelbybringingtm --Addition ofcolloidal silicic 70 further mixedwfith 180 lg'ralils 75 otvderfZOgra-Ins of cr'ystellized soasset sagn s mat- )lli'guid, 5o grams'foffsili'cih aciil jgel a liquid capable ofproducing dental cements,

which comprises adding silicic acid as an acetogel.

5. The process of making dental cements consisting in bringing togetherpulverulent aluminum compounds containing oxygen with liquids capable ofproducing dental cements with said compounds and adding silicic acid incolloidal condition.

6. The improvement in the process of making dental cements made bybringing together aluminum silicates and liquids capable of producingdental cements with said aluminum silicates, which comprises addingsilicic acid in colloidal condition.

7. The process of making dental cements consisting in bringing togetherpulverulent aluminum potassium silicate with liquids capable ofproducing dental cements with said aluminum potassium silicate andadding silicic acid in colloidal condition.

8. The process of making dental cements consisting in bringing togetherpulverulent metallic compounds capable of forming a solid compoundcomprising a silico .phosphate salt and phosphoric compounds containinoxygen and adding silicic acid in colloi al condition.

i .9. The process of making dental cements consisting in bringingtogether pulverulent metallic compounds capa le of forming a solidcompound comprlsing a silico phate salt and a hosphoric acid and asilicic acid in colloidal condition.

10. The process of making dental cements consisting in 'brin ing toether pulverulent metallic compounds capaile of forming a solid compoundcomprising a silico phosphate salt and orthophosphoric acid andaddingrsilicic acid in colloidal condition.

11 he process of making dental cements consisting in bringing togetherpulverulent metallic compounds capable of forming a solid compoundcomprising a silico phosphate salt and phosphoric compounds containingoxygen and adding a el of silicic acid in the form of an emulsoid.

12. The rocess of making dental cements consisting in bringin togetherpulverulent aluminum potassium silicate with orthophosphoric acidandadding an acetogel of silicic acid in the form of an emulsoid.

hosding In testimony, that I claim the foregoing as my invention, I havesigned my name this eleventh day of May, 1920.

. SALLY SCHIFF.

